The present invention relates generally to plasma cutting/gouging systems and, more particularly, to an apparatus and method for automatically detecting plasma cutting/gouging parameters via pressure decay. Typically, to perform a plasma cutting operation, a user must install the proper cutting consumables to the plasma torch, adjust the gas pressure supplied to the plasma torch, and adjust the pilot current supplied to the plasma torch by placing a user interface selector switch to the proper position. To change over to a plasma gouging operation, the user must install a different set of consumables to the plasma torch, readjust the gas pressure supplied to the plasma torch, and toggle the user interface selector switch to a gouging position, which will adjust the pilot current to a level sufficient for gouging. The change from a plasma cutting operation over to a plasma gouging operation and vice-versa helps to ensure that the correct plasma parameters are set to optimal levels for the type of consumable for the operation to be performed. However, an inexperienced or careless user may not properly set the levels for the type of consumable for the operation to be performed.
Additionally, when a different length of torch is installed on a plasma power source, a longer length of hose will cause a different pressure drop through the length of the torch than a shorter length of hose. As such, the pressure at the torch head may be either greater or lesser than the desired pressure, depending on the torch length. A user will typically not adjust a manually controlled gas system to an optimal level based on torch length. Therefore cutting performance, arc stability, and consumable life may be less than optimal.
It would therefore be desirable to have an apparatus and method capable of detecting the consumable type or length of torch installed on the plasma power source and capable of automatically adjusting plasma operation parameters to an optimal level.